Boltar wrote:
"Richard J." wrote in message
...
Boltar wrote:
"Richard J." wrote in message
...

Unprotected 3rd rail would not be allowed today on an entirely
new railway, but that has nothing to do with mixing tube and
mainline, both of which use the same technology at Richmond,
except that LU is 4-rail rather than 3-rail.

I never said that it did. Its to do with what happens to the
different types of trains if they collide with each other. Tube
trains usually come off worse because the buffer beam of the
mainline train hits the tube train on its body rather than its
buffers.

"Usually"? Which crashes between tube stock and mainline trains
did you have in mind for this statistical comment?

Figure of speech ok? Listen pal , I'm just trying to have an
interesting discussion here. If you want to have a flame war go
find some other patsy.

All I'm trying to do is to understand your reasoning. You say that the
HSE wouldn't allow a new situation where tube and mainline trains share
the same track, and cite the vulnerability of tube trains in a crash.
But that's not the logic that was followed after the Ladbroke Grove
crash where the leading car of the 165 was destroyed by impact with the
HST power car. The solution was not to segregate DMUs and HSTs but to
improve safety systems to reduce the risk of a collision. It seems to
me that the same principle would apply to any future tube/mainline track
sharing.
--
Richard J.
(to e-mail me, swap uk and yon in address)